CHEM2004                                                               Name_________________________

Exam 3a                                                                    Fall 2009

 

Show Work

 

1.         Determine the category of acidity for each of the following ions:            (10 points)

 

Pt ^{+ 4}    -

 

Ru ^{+ 3} -

  

Ca ^{+ 2} -

  

Br ^{+ 7} -

  

Cs ⁺ -

  

2.         Calculate pKb for each of the following:                     (6 points)

 

NpO ₆ ^{- 5}    

 

PO ₄ ^{- 3} 

 

NO ₃ ^-  

 

3.         Classify each oxoanion in question 2 in terms of basicity.            (6 points)

 

NpO ₆ ^{- 5}   

 

PO ₄ ^{- 3} 

 

NO ₃ ^-  

 

4.         Using the quick estimate method, determine the basicity category for:    (4 points)

 

WO ₄ ^{- 2}

 

IO ₆ ^{- 5}

 

5.         Calculate the pH for each ion below and tell the expected form in normal water and in acid waters.                                  (12 points)

 

	pH	normal water	acid water
Co + 2
Ru + 5
Pd + 2
Hf + 4